MEXICO CITY – The Roman Catholic Church called on doctors in Mexico City yesterday not to perform abortions and lamented the city's decision to legalize the procedure in the first 12 weeks of pregnancy.

The church has vowed to continue its anti-abortion campaign even through it is under investigation for possibly violating Mexican laws forbidding the church's participation in politics.

Mexico City officials have said doctors at city-run hospitals cannot refuse to perform abortions based on personal moral objection, but in a letter read at Sunday Mass, Cardinal Norberto Rivera Carrera said they could.

Archdiocese spokesman Hugo Valdemar Romero has said those who performed abortions and lawmakers who supported the legalization will be excommunicated.

Mexico City Mayor Marcelo Ebrard, whose leftist Democratic Revolution Party backed the bill approved by city lawmakers last week, said he would not be deterred by the church's statements.